Beef cows cannot live without minerals and vitamins, which are often deficient or biologically unavailable in many overwintering forage.
I advise people to put loose mineral on a regular basis for their gestating cows, so all essential mineral and vitamin requirements are supplemented. Unfortunately, some people don’t always feed enough mineral. With a little effort, cattle producers should calculate the proper amount of mineral, monitor mineral intake and take any action to correct poor consumption.
Good mineral intake by the pregnant cow herd is important at this time of year. Not only does good mineral intake maintain or build good mineral status required by their vital body tissues and immune system, it plays a big part in the last trimester of pregnancy in spring cows.
Pre-calving beef cows on a poor mineral feeding program deplete their own limited trace mineral reserves, even before their calves become mineral deficient and they themselves are adversely affected. It is estimated the late-gestation fetus (and placental tissues) use up to 30 per cent of the pre-calving cow’s daily requirements for essential trace minerals.
Since, the developing fetus is totally dependent upon the availability of essential minerals travelling through the placenta from its mothers’ blood, it uses its own natural ability to store certain trace minerals such as iron, copper, zinc, manganese, and selenium. It’s a natural instinct of post-calving survival, since colostrum and milk are low in these trace minerals.
For example, selenium status in fetal and newborn calf is only a reflection of the selenium and vitamin E status of its mother during gestation — white muscle disease in newborn calves is cited as a direct result of selenium deficiency in freshened beef cows.
To prevent mineral (and vitamin) deficiencies, producers should follow the daily recommendations printed on the feed label sewn to each commercial bag of cattle mineral. Most feed companies recommend that between 56 to 112 grams (re: two to four oz.) of salt-free mineral per cow per day. If salt makes up at least 25 per cent of this mineral, one should adjust mineral intakes, accordingly.
By my calculations, I use 80 g x three days of feeding x number of cows and then round off to the number of bags that is needed. For a 200 cow-calf operation: (80 g x three days x 200 days) /25-kg bags = two bags/three days should be provided.
From my own practical experience, here are a few considerations I find work to achieve daily mineral consumption goals:
- Invest in a durable mineral feeder — I am not a particular fan of wooden boxes, oil drums cut in half or even feed bunks to feed mineral to cattle. A good mineral feeder should be easily accessible to all cows, but protects mineral from the effects of water, wind, and sunshine.
Note — A friend of mine that owns about 200 beef cows mounts each durable plastic feeder on a truck tire to keep mineral out of the rain or snow as well as preventing the odd cow from stepping right into the feeder (see photo at top of page).
- Mineral feeder placement is important — It is also recommended portable mineral feeders should be located where cattle will make frequent visits. Moving mineral stations closer to water sources generally increases mineral intake by cows, while moving feeders farther back from the water will often decrease mineral intake. It is always a good idea to have enough mineral feeders for the whole herd; one standard recommendation is one feeding station for every 30 to 50 cows.
- Check mineral feeders every few days — At the beginning of the winter, mineral consumption by beef cows is often higher than the normal. However, as cows get used to their new overwinter diets, free-choice mineral feeding tends to adjust itself. Some producers mix salt with their purchased mineral, in order to either increase or decrease cow mineral intake. It is common to mix 1/3 salt with 2/3 mineral, and feed it.
- Clean and repair mineral feeders — Cattle don’t like to eat stale or leftover hardened mineral. I have seen cattle overeat fresh mineral, when feeders that were fully stocked once again, after not being cleaned for weeks. Damaged mineral feeders (torn rubber flap) should be fixed, while broken or excessively damaged feeders should be replaced.
These points remind me of a frugal producer I knew years ago, who didn’t want to spend money on a feeder. He used to pour one-half bag of cattle mineral on the ground in front of the cows each morning. By late afternoon, what wasn’t trampled was magically soaked into the wet snow. From the amount of mineral that was wasted, he could have bought an excellent quality mineral feeder, filled it with the proper type of mineral, assuring his cows met their gestation mineral and vitamin requirements during the winter.